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Cleaning Process for Cu(P) Anodes

IP.com Disclosure Number: IPCOM000110742D
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 1 page(s) / 77K

Publishing Venue

IBM

Related People

Chang, I: AUTHOR [+4]

Abstract

A procedure is disclosed for the cleaning of phosphorus-containing copper anodes for use in acid-copper electroplating processes. The disclosed procedure is an improvement over the currently-recommended procedure, shortening the time required and replacing unreliable and hazardous processes.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Cleaning Process for Cu(P) Anodes

      A procedure is disclosed for the cleaning of
phosphorus-containing copper anodes for use in acid-copper
electroplating processes.   The disclosed procedure is an improvement
over the currently-recommended procedure, shortening the time
required and replacing unreliable and hazardous processes.

      Acid copper plating is best accomplished with copper anodes,
which dissolve with the passage of current, thereby replenishing the
solution copper ions that are depleted by the plating process.  Pure
copper anodes are well known not to work satisfactorily; they form a
non-adherent anodic product that rapidly degrades the quality of the
product being plated.  The anode material generally used is copper
containing a small amount of phosphorus, typically on the order of
0.05 wt. %.

      The Cu(P) anodes perform well only if they are properly
prepared before they are used.  The last step of the preparation is
the passage of current in the chloride-containing plating solution,
thereby forming an adherent black anodic film.  A good anode film
results in good stability of the organic additive in the plating
solution and prevents non-adherent particulates from being produced.
In order to form a good anode film, however, the Cu(P) material must
first be thoroughly cleaned.

      The conventional cleaning of Cu(P) is a tedious and unpleasant
process, with the risk of exposure of personnel to the hazardous
chemical used.  The first step is the removal of any organic
contamination in a soak of at least one hour in ho...